Introduction > Definition Outline Definitions Additive measures: ( X, A ) a measurable space; then, a set function µ is an additive measure if it satisfies (i) µ ( A ) ≥ 0 for all A ∈ A , (ii) µ ( X ) ≤ ∞ i =1 A i ) = � ∞ (iii) µ ( ∪ ∞ i =1 µ ( A i ) for every countable sequence A i ( i ≥ 1) of A that is pairwise disjoint (i.e,. A i ∩ A j = ∅ when i � = j ). Vicen¸ c Torra; Non-additive (fuzzy) measures LFSC 2013 11 / 60
Introduction > Definition Outline Definitions Additive measures: ( X, A ) a measurable space; then, a set function µ is an additive measure if it satisfies (i) µ ( A ) ≥ 0 for all A ∈ A , (ii) µ ( X ) ≤ ∞ i =1 A i ) = � ∞ (iii) µ ( ∪ ∞ i =1 µ ( A i ) for every countable sequence A i ( i ≥ 1) of A that is pairwise disjoint (i.e,. A i ∩ A j = ∅ when i � = j ). Finite case: µ ( A ∪ B ) = µ ( A ) + µ ( B ) for disjoint A , B Vicen¸ c Torra; Non-additive (fuzzy) measures LFSC 2013 11 / 60
Introduction > Definition Outline Definitions Non-additive measures: ( X, A ) a measurable space, a non-additive (fuzzy) measure µ on ( X, A ) is a set function µ : A → [0 , 1] satisfying the following axioms: (i) µ ( ∅ ) = 0 , µ ( X ) = 1 (boundary conditions) (ii) A ⊆ B implies µ ( A ) ≤ µ ( B ) (monotonicity) Vicen¸ c Torra; Non-additive (fuzzy) measures LFSC 2013 12 / 60
Introduction > Differences Outline Differences Non-additive measures vs. additive measures: • In additive measures: µ ( A ) = � x ∈ A p x Vicen¸ c Torra; Non-additive (fuzzy) measures LFSC 2013 13 / 60
Introduction > Differences Outline Differences Non-additive measures vs. additive measures: • In additive measures: µ ( A ) = � x ∈ A p x • In non-additive measures: additivity no longer a constraint → three cases possible ◦ µ ( A ) = � x ∈ A p x Vicen¸ c Torra; Non-additive (fuzzy) measures LFSC 2013 13 / 60
Introduction > Differences Outline Differences Non-additive measures vs. additive measures: • In additive measures: µ ( A ) = � x ∈ A p x • In non-additive measures: additivity no longer a constraint → three cases possible ◦ µ ( A ) = � x ∈ A p x ◦ µ ( A ) < � x ∈ A p x Vicen¸ c Torra; Non-additive (fuzzy) measures LFSC 2013 13 / 60
Introduction > Differences Outline Differences Non-additive measures vs. additive measures: • In additive measures: µ ( A ) = � x ∈ A p x • In non-additive measures: additivity no longer a constraint → three cases possible ◦ µ ( A ) = � x ∈ A p x ◦ µ ( A ) < � x ∈ A p x ◦ µ ( A ) > � x ∈ A p x Vicen¸ c Torra; Non-additive (fuzzy) measures LFSC 2013 13 / 60
Introduction > Differences Outline Differences Non-additive measures vs. additive measures: • Is non-additivity useful ? Vicen¸ c Torra; Non-additive (fuzzy) measures LFSC 2013 14 / 60
Introduction > Differences Outline Differences Non-additive measures vs. additive measures: • Is non-additivity useful ? Yes Vicen¸ c Torra; Non-additive (fuzzy) measures LFSC 2013 14 / 60
Introduction > Differences Outline Differences Non-additive measures vs. additive measures: • Is non-additivity useful ? Yes • Why? Vicen¸ c Torra; Non-additive (fuzzy) measures LFSC 2013 14 / 60
Introduction > Differences Outline Differences Non-additive measures vs. additive measures: • Is non-additivity useful ? Yes • Why? some cases represent interactions ◦ µ ( A ) = � x ∈ A p x (no interaction) Vicen¸ c Torra; Non-additive (fuzzy) measures LFSC 2013 14 / 60
Introduction > Differences Outline Differences Non-additive measures vs. additive measures: • Is non-additivity useful ? Yes • Why? some cases represent interactions ◦ µ ( A ) = � x ∈ A p x (no interaction) ◦ µ ( A ) < � x ∈ A p x (negative interaction) Vicen¸ c Torra; Non-additive (fuzzy) measures LFSC 2013 14 / 60
Introduction > Differences Outline Differences Non-additive measures vs. additive measures: • Is non-additivity useful ? Yes • Why? some cases represent interactions ◦ µ ( A ) = � x ∈ A p x (no interaction) ◦ µ ( A ) < � x ∈ A p x (negative interaction) ◦ µ ( A ) > � x ∈ A p x (positive interaction) Vicen¸ c Torra; Non-additive (fuzzy) measures LFSC 2013 14 / 60
Introduction > Number of parameters Outline Number of parameters Non-additive measures vs. additive measures: • How to define an additive measure on X ? Vicen¸ c Torra; Non-additive (fuzzy) measures LFSC 2013 15 / 60
Introduction > Number of parameters Outline Number of parameters Non-additive measures vs. additive measures: • How to define an additive measure on X ? One probability value for each element → | X | values Vicen¸ c Torra; Non-additive (fuzzy) measures LFSC 2013 15 / 60
Introduction > Number of parameters Outline Number of parameters Non-additive measures vs. additive measures: • How to define an additive measure on X ? One probability value for each element → | X | values • How to define a non-additive measure? Vicen¸ c Torra; Non-additive (fuzzy) measures LFSC 2013 15 / 60
Introduction > Number of parameters Outline Number of parameters Non-additive measures vs. additive measures: • How to define an additive measure on X ? One probability value for each element → | X | values • How to define a non-additive measure? One value for each set → 2 | X | values Vicen¸ c Torra; Non-additive (fuzzy) measures LFSC 2013 15 / 60
Introduction > What to do? Outline What can we do with a measure? Vicen¸ c Torra; Non-additive (fuzzy) measures LFSC 2013 16 / 60
Introduction > What to do? Outline What can we do with a measure? Non-additive measures and additive measures: • Integrate a function f with respect to a measure: Vicen¸ c Torra; Non-additive (fuzzy) measures LFSC 2013 16 / 60
Introduction > What to do? Outline What can we do with a measure? Non-additive measures and additive measures: • Integrate a function f with respect to a measure: ◦ Integral w.r.t. additive measure p Vicen¸ c Torra; Non-additive (fuzzy) measures LFSC 2013 16 / 60
Introduction > What to do? Outline What can we do with a measure? Non-additive measures and additive measures: • Integrate a function f with respect to a measure: ◦ Integral w.r.t. additive measure p → expectation � p x f ( x ) � − → Lebesgue integral (continuous case: fdp ) Vicen¸ c Torra; Non-additive (fuzzy) measures LFSC 2013 16 / 60
Introduction > What to do? Outline What can we do with a measure? Non-additive measures and additive measures: • Integrate a function f with respect to a measure: ◦ Integral w.r.t. additive measure p → expectation � p x f ( x ) � − → Lebesgue integral (continuous case: fdp ) ◦ Integral w.r.t. non-additive measure µ → expectation like N � f ( x σ ( i ) )[ µ ( A σ ( i ) ) − µ ( A σ ( i − 1) )] i =1 � − → Choquet integral (continuous case: ( C ) fdµ ) Vicen¸ c Torra; Non-additive (fuzzy) measures LFSC 2013 16 / 60
Introduction > What to do? Outline What can we do with a measure? Non-additive measures and additive measures: • Integrate a function f with respect to a measure: ◦ Integral w.r.t. additive measure p → expectation � p x f ( x ) � − → Lebesgue integral (continuous case: fdp ) ◦ Integral w.r.t. non-additive measure µ → expectation like N � f ( x σ ( i ) )[ µ ( A σ ( i ) ) − µ ( A σ ( i − 1) )] i =1 � − → Choquet integral (continuous case: ( C ) fdµ ) The Choquet integral is a Lebesgue integral when the measure is additive Vicen¸ c Torra; Non-additive (fuzzy) measures LFSC 2013 16 / 60
Outline Applications LFSC 2013 17 / 60
Applications > Decision Making Outline Example Decision making: Ellsberg paradox (Ellsberg, 1961), an urn, 90 balls ... Color of balls Red Black Yellow Number of balls 30 60 $ 100 0 0 f R $ 0 $ 100 0 f B $ 100 0 $ 100 f RY $ 0 $ 100 $ 100 f BY • Usual (most people’s) preferences ◦ f B ≺ f R LFSC 2013 18 / 60
Applications > Decision Making Outline Example Decision making: Ellsberg paradox (Ellsberg, 1961), an urn, 90 balls ... Color of balls Red Black Yellow Number of balls 30 60 $ 100 0 0 f R $ 0 $ 100 0 f B $ 100 0 $ 100 f RY $ 0 $ 100 $ 100 f BY • Usual (most people’s) preferences ◦ f B ≺ f R ◦ f RY ≺ f BY LFSC 2013 18 / 60
Applications > Decision Making Outline Example Decision making: Ellsberg paradox (Ellsberg, 1961), an urn, 90 balls ... Color of balls Red Black Yellow Number of balls 30 60 $ 100 0 0 f R $ 0 $ 100 0 f B $ 100 0 $ 100 f RY $ 0 $ 100 $ 100 f BY • Usual (most people’s) preferences ◦ f B ≺ f R ◦ f RY ≺ f BY • No solution exist with additive measures, but can be solved with non-additive ones LFSC 2013 18 / 60
Applications > Subjective Evaluation Outline Applications Subjective Evaluation: Subjective evaluation and application field for non-additive (fuzzy) measures from the beginning. (Sugeno, 1974, p.2): “The purposes of this dissertation are to propose the concept of fuzzy measures and integrals [11,12] as a way for expressing human subjectivity and to discuss their applications.” Vicen¸ c Torra; Non-additive (fuzzy) measures LFSC 2013 19 / 60
Applications > Subjective Evaluation Outline Applications Definition of Subjective Evaluation: (Dubois and Prade, 1997) “Formally speaking, the subjective evaluation problem can be viewed as the synthesis, the identification of a function which maps the attribute values describing the situation to evaluate into a discrete domain (classification), or a continuous one (absolute evaluation). More generally, we may look for the degree of membership of the situation to a category, or have a function yielding a fuzzy evaluation. This function is in general not available as such, but is implicitly, and partially, described in terms of criteria, or by means of expert rules, or through some fuzzy algorithm. It may also happen that the function is only partially known by exemplification through prototypical examples of situations for which the evaluation is available.” Vicen¸ c Torra; Non-additive (fuzzy) measures LFSC 2013 20 / 60
Applications > Subjective Evaluation Outline Example Example: (Grabish, 1995) Evaluation of students • students (A, B, C) on three subjects (M, P, L) Ada, Byron, Countess; maths, physics, literature • Marks: Student M P L Ada 18 16 10 f A Byron 10 12 18 f B Countess 14 15 15 f C • Preferences: ◦ Assign the same weight to mathematics and physics, and more weight to this subjects than to literature. ◦ Represent the following preference on the students: B ≺ A ≺ C. Vicen¸ c Torra; Non-additive (fuzzy) measures LFSC 2013 21 / 60
Applications > Subjective Evaluation Outline Example Example: (Grabish, 1995) • No solution with additive measures We can use non-additive measures (with the Choquet integral) Vicen¸ c Torra; Non-additive (fuzzy) measures LFSC 2013 22 / 60
Outline Distorted Probabilities LFSC 2013 23 / 60
Distorted Probabilities > Introduction Outline Distorted Probabilities: introduction An open question: Vicen¸ c Torra; Non-additive (fuzzy) measures LFSC 2013 24 / 60
Distorted Probabilities > Introduction Outline Distorted Probabilities: introduction An open question: Non-additive measures vs. additive measures: How to define a non-additive measure? One value for each set → 2 | X | values Vicen¸ c Torra; Non-additive (fuzzy) measures LFSC 2013 24 / 60
Distorted Probabilities > Introduction Outline Distorted Probabilities: introduction An open question: Non-additive measures vs. additive measures: How to define a non-additive measure? One value for each set → 2 | X | values A possible solution: Vicen¸ c Torra; Non-additive (fuzzy) measures LFSC 2013 24 / 60
Distorted Probabilities > Introduction Outline Distorted Probabilities: introduction An open question: Non-additive measures vs. additive measures: How to define a non-additive measure? One value for each set → 2 | X | values A possible solution: Distorted Probabilities. • Compact representation of non-additive measures: Vicen¸ c Torra; Non-additive (fuzzy) measures LFSC 2013 24 / 60
Distorted Probabilities > Introduction Outline Distorted Probabilities: introduction An open question: Non-additive measures vs. additive measures: How to define a non-additive measure? One value for each set → 2 | X | values A possible solution: Distorted Probabilities. • Compact representation of non-additive measures: ◦ Only | X | values (a probability) and a function (distorting function) Vicen¸ c Torra; Non-additive (fuzzy) measures LFSC 2013 24 / 60
Distorted Probabilities > Definition Outline Distorted Probabilities: Definition • Representation of a fuzzy measure: ◦ f and P represent a fuzzy measure µ , iff µ ( A ) = f ( P ( A )) for all A ∈ 2 X f a real-valued function, P a probability measure on ( X, 2 X ) ◦ f is strictly increasing w.r.t. a probability measure P iff P ( A ) < P ( B ) implies f ( P ( A )) < f ( P ( B )) ◦ f is nondecreasing w.r.t. a probability measure P iff P ( A ) < P ( B ) implies f ( P ( A )) ≤ f ( P ( B )) Vicen¸ c Torra; Non-additive (fuzzy) measures LFSC 2013 25 / 60
Distorted Probabilities > Definition Outline Distorted Probabilities: Definition • Representation of a fuzzy measure: distorted probability ◦ f and P represent a fuzzy measure µ , iff µ ( A ) = f ( P ( A )) for all A ∈ 2 X f a real-valued function, P a probability measure on ( X, 2 X ) ◦ f is strictly increasing w.r.t. a probability measure P iff P ( A ) < P ( B ) implies f ( P ( A )) < f ( P ( B )) ◦ f is nondecreasing w.r.t. a probability measure P iff P ( A ) < P ( B ) implies f ( P ( A )) ≤ f ( P ( B )) ◦ µ is a distorted probability if µ is represented by a probability distribution P and a function f nondecreasing w.r.t. a probability P . Vicen¸ c Torra; Non-additive (fuzzy) measures LFSC 2013 26 / 60
Distorted Probabilities > Definition Outline Distorted Probabilities: Definition • Representation of a fuzzy measure: distorted probability ◦ µ is a distorted probability if µ is represented by a probability distribution P and a function f nondecreasing w.r.t. a probability P . • So, for a given reference set X we need: ◦ Probability distribution on X : p ( x ) for all x ∈ X ◦ Distortion function f on the probability measure: f ( P ( A )) Vicen¸ c Torra; Non-additive (fuzzy) measures LFSC 2013 27 / 60
Distorted Probabilities > Application Outline Distorted Probabilities: Application • Given a distorted probability ... ... we can apply any fuzzy integral • E.g. ◦ the Choquet integral ◦ the Sugeno integral Vicen¸ c Torra; Non-additive (fuzzy) measures LFSC 2013 28 / 60
Distorted Probabilities > Application Outline Distorted Probabilities: Application • Distorted probability and Choquet integral: ◦ The WOWA operator can be represented as a Choquet integral with a distorted probability. ⋆ WOWA generalizes both the WM and the OWA, using both WM weights and OWA weights. ◦ From the distorted probability perspective, in WOWA: ⋆ the WM weights correspond to the probability distribution ⋆ the OWA weights are used to the construct the distortion function Vicen¸ c Torra; Non-additive (fuzzy) measures LFSC 2013 29 / 60
Distorted Probabilities > Properties Outline Distorted Probabilities: Properties • Some distorted probabilities are not decomposable fuzzy measures. • Some distorted probabilities cannot be represented easily with other families of fuzzy measures → they really belong to another family. Vicen¸ c Torra; Non-additive (fuzzy) measures LFSC 2013 30 / 60
Distorted Probabilities > Properties Outline Distorted Probabilities: Properties • Some distorted probabilities are not decomposable fuzzy measures. • Some distorted probabilities cannot be represented easily with other families of fuzzy measures → they really belong to another family. • 1st. example (I): ◦ µ on X = { a, b, c } with p ( a ) = 0 . 2 , p ( b ) = 0 . 35 , p ( c ) = 0 . 45 , and 0 if x < 0 . 5 0 . 2 if 0 . 5 ≤ x < 0 . 6 f ( x ) = if 0 . 6 ≤ x < 0 . 85 0 . 4 if 0 . 85 ≤ x ≤ 1 . 0 1 . 0 Vicen¸ c Torra; Non-additive (fuzzy) measures LFSC 2013 30 / 60
Distorted Probabilities > Properties Outline Distorted Probabilities: Properties • Some distorted probabilities are not decomposable fuzzy measures. • Some distorted probabilities cannot be represented easily with other families of fuzzy measures. • 1st. example (II): ◦ µ ( ∅ ) = 0 , µ ( { a } ) = 0 , µ ( { b } ) = 0 , µ ( { c } ) = 0 , µ ( { a, b } ) = 0 . 2 , µ ( { a, c } ) = 0 . 4 , µ ( { b, c } ) = 0 . 4 , µ ( { a, b, c } ) = 1 ◦ µ is a DP but not a ⊥ -decomposable fuzzy measure because, there is no t-conorm s.t. ⊥ (0 , 0) � = 0 → as µ ( { a, b } ) = 0 . 2 when µ ( { a } ) = 0 and µ ( { b } ) = 0 , we would require 0 . 2 = µ ( { a, b } ) = ⊥ ( µ ( { a } ) , µ ( { b } )) = ⊥ (0 , 0) . Vicen¸ c Torra; Non-additive (fuzzy) measures LFSC 2013 31 / 60
Distorted Probabilities > Properties Outline Distorted Probabilities: Properties • Some distorted probabilities are not decomposable fuzzy measures. • Some distorted probabilities cannot be represented easily with other families of fuzzy measures. • 2nd. example (I): ◦ µ p , w over X = { x 1 , x 2 , x 3 , x 4 , x 5 } from ( probability distribution ) p = (0 . 2 , 0 . 3 , 0 . 1 , 0 . 2 , 0 . 1) , and function ( from w = (0 . 1 , 0 . 2 , 0 . 4 , 0 . 2 , 0 . 1) ): Vicen¸ c Torra; Non-additive (fuzzy) measures LFSC 2013 32 / 60
Distorted Probabilities > Properties Outline Distorted Probabilities: Properties • Some distorted probabilities are not decomposable fuzzy measures. • Some distorted probabilities cannot be represented easily with other families of fuzzy measures. • 2nd. example (II): ◦ µ p , w is a 5 -additive fuzzy measure because m ( A ) � = 0 for all A . ◦ E.g., m ( { x 1 , x 2 , x 3 , x 4 , x 5 } ) = 0 . 50746528 , m ( { x 1 , x 2 , x 3 , x 4 } ) = − 0 . 2537326 . There is no k -additive fuzzy measure equivalent to µ p , w for k < 5 . Vicen¸ c Torra; Non-additive (fuzzy) measures LFSC 2013 33 / 60
Outline m-dimensional Distorted Probabilities LFSC 2013 34 / 60
m-Dimensional Distorted Probabilities > Definition Outline m-Dimensional Distorted Probabilities Justification: Why any extension of distorted probabilities? LFSC 2013 35 / 60
m-Dimensional Distorted Probabilities > Definition Outline m-Dimensional Distorted Probabilities Justification: Why any extension of distorted probabilities? The number of distorted probabilities. LFSC 2013 35 / 60
m-Dimensional Distorted Probabilities > Definition Outline m-Dimensional Distorted Probabilities Justification: Why any extension of distorted probabilities? The number of distorted probabilities. Observe the following • For X = { 1 , 2 , 3 } , 2/8 of distorted probabilities. • For larger sets X ... ... the proportion of distorted probabilities decreases rapidly • For µ ( { 1 } ) ≤ µ ( { 2 } ) ≤ . . . | X | Number of possible orderings for Number of possible orderings for Distorted Probabilities Fuzzy Measures 1 1 1 2 1 1 3 2 8 4 14 70016 O ( 10 12 ) 5 546 6 215470 – LFSC 2013 35 / 60
m-Dimensional Distorted Probabilities > Definition Outline m-Dimensional Distorted Probabilities Justification: Why any extension of distorted probabilities? The number of distorted probabilities. Goal: • To cover a larger region of the space of fuzzy measures Unconstrained fuzzy measures DP → (similar to the property of k -additive fuzzy measures) DP 1 ,X ⊂ DP 2 ,X ⊂ DP 3 ,X · · · ⊂ DP | X | ,X LFSC 2013 36 / 60
m-Dimensional Distorted Probabilities > Definition Outline m-Dimensional Distorted Probabilities • In distorted probabilities: ◦ One probability distribution ◦ One function f to distort the probabilities • Extension to: ◦ m probability distributions ◦ One function f to distort/combine the probabilities LFSC 2013 37 / 60
m-Dimensional Distorted Probabilities > Definition Outline m-Dimensional Distorted Probabilities • In distorted probabilities: ◦ One probability distribution ◦ One function f to distort the probabilities • Extension to: ◦ m probability distributions P i ⋆ Each P i defined on X i ⋆ Each X i is a partition element of X (a dimension) ◦ One function f to distort/combine the probabilities LFSC 2013 38 / 60
m-Dimensional Distorted Probabilities > Definition Outline m-Dimensional Distorted Probabilities: Example • Running example: ◦ A fuzzy measure that is not a distorted probability: µ ( ∅ ) = 0 µ ( { M, L } ) = 0 . 9 µ ( { M } ) = 0 . 45 µ ( { P, L } ) = 0 . 9 µ ( { P } ) = 0 . 45 µ ( { M, P } ) = 0 . 5 µ ( { L } ) = 0 . 3 µ ( { M, P, L } ) = 1 ◦ Partition on X : ⋆ X 1 = { L } (Literary subjects) ⋆ X 2 = { M, P } (Scientific Subjects) LFSC 2013 39 / 60
m-Dimensional Distorted Probabilities > Definition Outline m-Dimensional Distorted Probabilities: Definition • m -dimensional distorted probabilities. ◦ µ is an at most m dimensional distorted probability if µ ( A ) = f ( P 1 ( A ∩ X 1 ) , P 2 ( A ∩ X 2 ) , · · · , P m ( A ∩ X m )) where, { X 1 , X 2 , · · · , X m } is a partition of X , P i are probabilities on ( X i , 2 X i ) , f is a function on R m strictly increasing with respect to the i -th axis for all i = 1 , 2 , . . . , m . • µ is an m -dimensional distorted probability if it is an at most m dimensional distorted probability but it is not an at most m − 1 dimensional. LFSC 2013 40 / 60
m-Dimensional Distorted Probabilities > Definition Outline m-Dimensional Distorted Probabilities: Example • Running example: a two dimensional distorted probability µ ( A ) = f ( P 1 ( A ∩ { L } ) , P 2 ( A ∩ { M, P } )) ◦ with partition on X = { M, L, P } 1. Literary subject { L } 2. Science subjects { M, P } , ◦ probabilities 1. P 1 ( { L } ) = 1 2. P 2 ( { M } ) = P 2 ( { P } ) = 0 . 5 , ◦ and distortion function f defined by { L } 1 0.3 0.9 1.0 0 ∅ 0 0.45 0.5 sets ∅ { M } , { P } { M,P } ∅ f 0.5 1 LFSC 2013 41 / 60
Outline Distorted Probabilities and Multisets an approach to define (simple) fuzzy measures on multisets LFSC 2013 42 / 60
DP and Multisets > Multisets Outline Distorted Probabilities and Multisets Multisets: elements can appear more than once • Defined in terms of count M : X → { 0 } ∪ N e.g. when X = { a, b, c, d } and M = { a, a, b, b, c, c, c } , count M ( a ) = 2 , count M ( b ) = 3 , count M ( c ) = 3 , count M ( d ) = 0 . • A and B multisets on X , then ◦ A ⊆ B if and only if count A ( x ) ≤ count B ( x ) for all x in X (used to define submultiset). ◦ A ∪ B : count A ∪ B ( x ) = max( count A ( x ) , count B ( x )) for all x in X . ◦ A ∩ B : count A ∩ B ( x ) = min( count A ( x ) , count B ( x )) for all x in X . LFSC 2013 43 / 60
DP and Multisets > Fuzzy Measure Outline Distorted Probabilities and Multisets Fuzzy measure on multiset: X a reference set, M a multiset on X s.t. M � = ∅ ; then, the function µ from ( M, P ( M )) to [0 , 1] is a fuzzy measure if the following holds: • µ ( ∅ ) = 0 and µ ( M ) = 1 • µ ( A ) ≤ µ ( B ) when A ⊆ B and B ⊆ M . LFSC 2013 44 / 60
DP and Multisets > Fuzzy Measure Outline Distorted Probabilities and Multisets Fuzzy measure on multiset: X a reference set, M a multiset on X s.t. M � = ∅ ; then, the function µ from ( M, P ( M )) to [0 , 1] is a fuzzy measure if the following holds: • µ ( ∅ ) = 0 and µ ( M ) = 1 • µ ( A ) ≤ µ ( B ) when A ⊆ B and B ⊆ M . How to define fuzzy measures?: LFSC 2013 44 / 60
DP and Multisets > Fuzzy Measure Outline Distorted Probabilities and Multisets Fuzzy measure on multiset: X a reference set, M a multiset on X s.t. M � = ∅ ; then, the function µ from ( M, P ( M )) to [0 , 1] is a fuzzy measure if the following holds: • µ ( ∅ ) = 0 and µ ( M ) = 1 • µ ( A ) ≤ µ ( B ) when A ⊆ B and B ⊆ M . How to define fuzzy measures?: • Even more parameters � x ∈ X count M ( x ) !! LFSC 2013 44 / 60
DP and Multisets > Fuzzy Measure Outline Distorted Probabilities and Multisets Fuzzy measure on multiset: X a reference set, M a multiset on X s.t. M � = ∅ ; then, the function µ from ( M, P ( M )) to [0 , 1] is a fuzzy measure if the following holds: • µ ( ∅ ) = 0 and µ ( M ) = 1 • µ ( A ) ≤ µ ( B ) when A ⊆ B and B ⊆ M . How to define fuzzy measures?: • Even more parameters � x ∈ X count M ( x ) !! We present two alternative (but related) approaches LFSC 2013 44 / 60
DP and Multisets > Fuzzy Measure Outline Distorted Probabilities and Multisets 1st approach: Definition based on a pseudoadditive integral: Nondecreasing function-based fuzzy measures • X a reference set, M a multiset on X and µ a ⊕ -decomposable fuzzy measure on X . Let f : [0 , ∞ ) → [0 , ∞ ) be a non-decreasing function with f (0) = 0 and f ( m ( M )) = 1 . Then, we define a fuzzy measure ν on P ( M ) by ν f ( A ) = f ( m ( A )) where m is the multiset function m : P ( M ) → [0 , ∞ ) defined by � m ( A ) = ( D ) count A dµ. LFSC 2013 45 / 60
DP and Multisets > Fuzzy Measure Outline Distorted Probabilities and Multisets 1st approach: Definition based on a pseudoadditive integral: Nondecreasing function-based fuzzy measures • X a reference set, M a multiset on X and µ a ⊕ -decomposable fuzzy measure on X . Let f : [0 , ∞ ) → [0 , ∞ ) be a non-decreasing function with f (0) = 0 and f ( m ( M )) = 1 . Then, we define a fuzzy measure ν on P ( M ) by ν f ( A ) = f ( m ( A )) where m is the multiset function m : P ( M ) → [0 , ∞ ) defined by � m ( A ) = ( D ) count A dµ. � • Rationale of the definition: ( C ) χ A dµ = µ ( A ) LFSC 2013 45 / 60
DP and Multisets > Fuzzy Measure Outline Distorted Probabilities and Multisets 1st approach: Definition based on a pseudoadditive integral: Nondecreasing function-based fuzzy measures • X a reference set, M a multiset on X and µ a ⊕ -decomposable fuzzy measure on X . Let f : [0 , ∞ ) → [0 , ∞ ) be a non-decreasing function with f (0) = 0 and f ( m ( M )) = 1 . Then, we define a fuzzy measure ν on P ( M ) by ν f ( A ) = f ( m ( A )) where m is the multiset function m : P ( M ) → [0 , ∞ ) defined by � m ( A ) = ( D ) count A dµ. � • Rationale of the definition: ( C ) χ A dµ = µ ( A ) • Properties: if A ⊆ B by the monotonicity of the integral m ( A ) ≤ m ( B ) → monotonicity condition of the fuzzy measure fulfilled LFSC 2013 45 / 60
DP and Multisets > Fuzzy Measure Outline Distorted Probabilities and Multisets 2nd approach: Definition based on prime numbers 1 : • Define � φ ( x ) count A ( x ) , n ( A ) := x ∈ X where φ is an injective function from X to the prime numbers, and let h be a non-decreasing function from N to [0 , 1] satisfying h (1) = 0 and h ( n ( M )) = 1 . We define the prime number-based fuzzy measure ν φ,h ( A ) = h ( n ( A )) . 1 and using the unique factorization of integers into prime numbers LFSC 2013 46 / 60
DP and Multisets > Fuzzy Measure Outline Distorted Probabilities and Multisets 2nd approach: Definition based on prime numbers 1 : • Define � φ ( x ) count A ( x ) , n ( A ) := x ∈ X where φ is an injective function from X to the prime numbers, and let h be a non-decreasing function from N to [0 , 1] satisfying h (1) = 0 and h ( n ( M )) = 1 . We define the prime number-based fuzzy measure ν φ,h ( A ) = h ( n ( A )) . Properties: if A � = B by the unique factorization n ( A ) � = n ( B ) if A ⊆ B by the factorization n ( A ) < n ( B ) → monotonicity condition of the fuzzy measure fulfilled 1 and using the unique factorization of integers into prime numbers LFSC 2013 46 / 60
DP and Multisets > Fuzzy Measure Outline Distorted Probabilities and Multisets Properties: • Fuzzy measures based on prime-number are a particular case of the 1st approach LFSC 2013 47 / 60
DP and Multisets > Fuzzy Measure Outline Distorted Probabilities and Multisets Properties: • Fuzzy measures based on prime-number are a particular case of the 1st approach • Neither the 1st nor the 2nd approach represent all possible fuzzy measures LFSC 2013 47 / 60
DP and Multisets > Fuzzy Measure Outline Distorted Probabilities and Multisets Properties: • Fuzzy measures based on prime-number are a particular case of the 1st approach • Neither the 1st nor the 2nd approach represent all possible fuzzy measures • It seems that there is some parallelism between prime-number based fuzzy measures and distorted probabilities ◦ f and the distortion ◦ φ and the probability distribution LFSC 2013 47 / 60
DP and Multisets > Fuzzy Measure Outline Distorted Probabilities and Multisets Properties: • Fuzzy measures based on prime-number are a particular case of the 1st approach • Neither the 1st nor the 2nd approach represent all possible fuzzy measures • It seems that there is some parallelism between prime-number based fuzzy measures and distorted probabilities ◦ f and the distortion ◦ φ and the probability distribution • Can we establish a relationship?? LFSC 2013 47 / 60
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